<!DOCTYPE html>
<html lang="en">

<head>
   <meta charset="UTF-8">
   <meta name="viewport"
      content="width=device-width, initial-scale=1.0,maximum-scale=1.0, minimum-scale=1.0, user-scalable=no">

   <meta http-equiv="X-UA-Compatible" content="ie=edge">
   <title>Document</title>
   <style>
      * {
         margin: 0;
         padding: 0;
      }



      header {
         margin: 100px auto;
      }

      div {
         width: 10%;
         height: 100px;

      }

      div:first-child {
         float: left;
         background-color: green;
      }

      div:last-child {
         float: left;
         background-color: pink;
      }

      div:nth-child(2) {
         float: left;
         background-color: greenyellow;
      }

      div:nth-child(3) {
         float: left;
         background-color: red;
      }
   </style>
</head>

<body>
   <header>
      <div></div>
      <div></div>
      <div></div>
      <div></div>
      <div></div>
   </header>

</body>

</html>